Regarding the lag:
how did you use Godot's engine's animation for the animation?
Did you tell it to animate all at once?
Or once one breaking animation is finished, it moves to the next?
Or did you create a timer that starts one animation after the other?
Did you loop through each breaking object?
My suspicion is that somewhere you're repeatedly and continuously looping through every breaking object, to check when to start the animation.
It's usually these loops through all items of object groups that cause lags like that from my experience.
Well when I said:
"The first time the evil alter ego showed up was spooky, it's really well done how the doll ran off."
I was talking about when I saw the evil doll for the first time quickly appear and then run off to the right out of the screen.
I found it spooky and well done.
So if that's what you mean I guess I saw it?
Well and thank you for making the game ;)